This is the fifth volume in the series on the subject of quark–gluon plasma, a unique phase created in heavy-ion collisions at high energy. It contains review articles by the world experts on various aspects of quark–gluon plasma taking into account the advances driven by the latest experimental data collected at both the Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC). The articles are pedagogical and comprehensive which can be helpful for both new researchers entering the field as well as the experienced physicists working on the subject.